Dihydroeugenol derivatives associated with blue LED light: A different form to face multidrug resistant (MDR) bacteria.

Eugenol has already had its pharmacological properties elucidated in previous studies, including antibacterial and antifungal properties. Based on such information, this study aimed to evaluate the antibacterial and modulatory activity of coumarin compounds prepared from dihydroeugenol and to associate them with blue LED light for the same activity. For this study, five of the substances available: compound 1 (C1), 8-methoxy-2-oxo-6-propyl-2H-chromen-3-carboxylic acid, compound (C2), 3-(hydroxy(4-nitrophenyl)methyl)-8- methoxy-6-propyl-2H-chromen-2-one, compound 7 (C3), 8-hydroxy-3-(4-nitrobenzoyl)-6-propyl-2H-chromen-2-one, compound 8 (C4), 3-(4-aminobenzoyl)-8-methoxy-6-propyl-2H-chromen-2-one and Compound 9 (C5), 8-methoxy-3-(4-nitrobenzoyl)-6-propyl-2H-chromen-2-one 2-one. To determine the MIC, the broth microdilution technique was used. The products were evaluated for their potential to modulate the activity of antibiotics. Afterward, the plates were submitted to blue LED light for 20 min. When exposed to LED, C3 exhibited a decrease in MIC for SA ATCC and C5 for EC ATCC, with an average of 645.08 µg/mL for both cases. C2 and C4 exhibited synergism in a greater number of situations. However, C3 showed promising activity against S. aureus. C1 and C2 already acted better against E. coli, with the difference that C1 acted better against these bacteria when associated with LED. In general, the compounds studied here exhibited good antibacterial activity when associated with LED.

Purification, partial characterization and immobilization of a mannose-specific lectin from seeds of Dioclea lasiophylla mart.

Lectin from the seeds of Dioclea lasiophylla (DlyL) was purified in a single step by affinity chromatography on a Sephadex® G-50 column. DlyL strongly agglutinated rabbit erythrocytes and was inhibited by monosaccharides (D-mannose and α-methyl-D-mannoside) and glycoproteins (ovalbumin and fetuin). Similar to other Diocleinae lectins, DlyL has three chains, α, ß and γ, with mass of 25,569 ± 2, 12,998 ± 1 and 12,588 ± 1 Da, respectively, and has no disulfide bonds. The hemagglutinating activity of DlyL was optimal in pH 8.0, stable at a temperature of 70 °C and decreased in EDTA solution, indicating that lectin activity is dependent on divalent metals. DlyL exhibited low toxicity on Artemia sp. nauplii, but this effect was dependent on the concentration of lectin in solution. DlyL immobilized on cyanogen bromide-activated Sepharose® 4B bound 0.917 mg of ovalbumin per cycle, showing the ability to become a tool for glycoproteomics studies.

Homologous Canavalia lectins elicit different patterns of antinociceptive responses.

Canavalia gladiata (CGL), C. maritima (ConM) and C. brasiliensis (ConBr) lectins were evaluated in nociception models. ConBr inhibited first (32%) and second (100%) phases of the formalin test; CGL inhibited only the first (74%) and ConM only the second (59%) phase. Hypernociception evaluated in the Von Frey test was inhibited by ConM (55%), CGL (41%) and ConBr (38%). Acetic acid-induced abdominal writhing was reduced by ConBr (66%), CGL (52%) and ConM (60%). ConBr and CGL effects were reversed by the lectin association with its ligand sugar. The antinociceptive activity of the structural homologous lectins was differentiated by potency, efficacy and mechanisms.